The three cubs are not actually hibernating, but they are showing the effects of a lack of food and what natural conditions (weather, length of daylight hours) dictate they should be doing. You will recall that the curators stopped actual feeding of the bears a few weeks ago, to mimic the lack of natural foods in the wild. The only food to be found now would be leftovers hidden in the grass and insects that are hidden as well.

The cubs respond by sleeping much longer and more often. They sleep at least 12-14 hours overnight and take numerous naps during the day.

Daytime naps may take place on the platform. Here they are at 1:00 in the afternoon.
Occasionally they awaken to do a bit of foraging.
Jessamine investigated the Acclimation Pen.
Then she tried out one of the culvert dens. None of the bears have actually slept in one of these.
Beignet stops by and engages in a bit of slo-mo play with Jessamine.
By 6:00 pm the three cubs were asleep in Jessamine’s daybed.
At 9:00 the next morning, the three cubs were still sleeping.

As we said, the cubs are slowing down noticeably and sleeping more and more. The question is: will they eventually stop waking and sleep for several days at a time? We’ll just have to wait and see.